Catheter device with detachable distal end

ABSTRACT

An atherectomy catheter includes an elongate catheter body, a cutter at a distal end of the catheter body, and a nosecone attached to a distal end of the catheter body. The cutter is configured to excise tissue from the body. The nosecone is configured to hold tissue excised from the cutter. The nosecone includes a distal section, a proximal section, and a connection mechanism that is configured to allow the distal section to attach and detach from the proximal section during use. The distal section includes a plug configured to sit within an inner diameter of the proximal section when the proximal section is connected to the distal section.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/345,483, filed Jun. 3, 2016, and titled “DETACHING NOSECONE FORCATHETER DEVICE,” the entirety of which is incorporated by referenceherein.

This application may be related to PCT Application WO 2014/142954entitled, “TISSUE COLLECTION DEVICE FOR CATHETER” filed on Mar. 15,2013, which is herein incorporated by reference in its entirety. Thisapplication may also be related to U.S. patent application Ser. No.13/175,232, filed Jul. 1, 2011, titled “ATHERECTOMY CATHETERS WITHLONGITUDINALLY DISPLACEABLE DRIVE SHAFTS,” now U.S. Pat. No. 9,345,510,which is herein incorporated by reference in its entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference in their entirety to the sameextent as if each individual publication or patent application wasspecifically and individually indicated to be incorporated by reference.

FIELD

This application is related to tissue collection devices that can beused with occlusion-crossing devices or systems such as atherectomycatheters. In particular, described herein are nosecones that can beused with catheter devices where the connection does not interfere withthe catheter device cutter and its function of cutting and clearing outdebulked tissue.

BACKGROUND

Peripheral artery disease (PAD) affects millions of people in the UnitedStates alone. PAD is a silent, dangerous disease that can havecatastrophic consequences when left untreated. PAD is the leading causeof amputation in patients over 50 and is responsible for approximately160,000 amputations in the United States each year.

Peripheral artery disease (PAD) is a progressive narrowing of the bloodvessels most often caused by atherosclerosis, the collection of plaqueor a fatty substance along the inner lining of the artery wall. Overtime, this substance hardens and thickens, which may interfere withblood circulation to the arms, legs, stomach and kidneys. This narrowingforms an occlusion, completely or partially restricting flow through theartery. Blood circulation to the brain and heart may be reduced,increasing the risk for stroke and heart disease.

Interventional treatments for PAD may include endarterectomy and/oratherectomy. Atherectomy offers a simple mechanical advantage overalternative therapies. Removing the majority of plaque mass (e.g.,debulking) may create a larger initial lumen and dramatically increasesthe compliance of the arterial wall. As a result, stent deployment isgreatly enhanced.

While atherectomy may provide a minimally invasive solution to clearingthe way for placement of stents within initially blocked arteries, thereremains a need to improve certain aspects of atherectomy catheterspresently available. For example, tissue collection and/or tissueremoval from the arteries is a common challenge during atherectomyprocedures. One mechanism for handling debulked tissue is to collect thetissue in a distal nosecone or collection chamber of the device.However, removing the tissue from the collection chamber or cleaning thechamber remains difficult. Accordingly, an atherectomy catheter thataddresses some of these problems is desired.

SUMMARY OF THE DISCLOSURE

In general, in one embodiment, an atherectomy catheter includes anelongate catheter body, a cutter at a distal end of the catheter body,and a nosecone attached to a distal end of the catheter body. The cutteris configured to excise tissue from the body. The nosecone is configuredto hold tissue excised from the cutter. The nosecone includes a distalsection, a proximal section, and a connection mechanism that isconfigured to allow the distal section to attach and detach from theproximal section during use. The distal section includes a plugconfigured to sit within an inner diameter of the proximal section whenthe proximal section is connected to the distal section.

This and other embodiments can include one or more of the followingfeatures. The nosecone can further include a hollow interior portionconfigured to receive excised tissue. The nosecone can be flexible. Theatherectomy catheter can further include a guidewire channel disposedalong an exterior of the nosecone. The guidewire channel can include adistal portion extending along the distal section of the nosecone and aproximal portion extending along the proximal section of the nosecone.The distal portion and proximal portion can be configured to align whenthe proximal section and the distal section are connected together. Thedistal portion and proximal portions can be configured to prevent theproximal section and distal sections from rotating relative to oneanother when a guidewire is placed therethrough. The connectionmechanism can further include a tab configured to be gripped through thedistal section of the nosecone to rotate the distal section relative tothe proximal section to activate or deactivate the connection mechanism.The connection mechanism can further include a cam and ball bearingconfigured to lock and unlock the proximal section relative to thedistal section. The connection mechanism can include a plurality of snaparms configured to extend into the proximal section and to interlockwith apertures on the proximal section. The snap arms can each include atab configured to fit within the apertures. The tabs can be chamferedalong a side edge such that rotation of the distal section towards thechamfered edges causes the distal section to automatically unlock fromthe proximal section. The nosecone can be configured to pivot away fromthe elongate catheter body to further expose the cutter. The cutter canbe configured to move axially into the nosecone to pack tissue.

In general, in one embodiment, an atherectomy catheter includes acatheter body having a catheter body proximal end, a catheter bodydistal end, a cutting window, a cutter exposable through the cuttingwindow, a nosecone, and a collar. A nosecone has a nosecone proximal endand a nosecone distal end. The nosecone proximal end is configured tocouple and decouple from the nosecone distal end. The collar has acollar inner surface configured to maintain a detachable connectionbetween the nosecone proximal end with the nosecone distal end.

This and other embodiments can include one or more of the followingfeatures. The nosecone can further include a hollow interior portionconfigured to receive excised tissue. The atherectomy catheter canfurther include a locking mechanism for maintaining connection betweenthe nosecone proximal end with the nosecone distal end. The lockingmechanism components can be disposed on the nosecone proximal end, thecollar, the nosecone distal end, or a combination thereof. The lockingmechanism can utilize corresponding threads for mating the detachablenosecone proximal end to the nosecone distal end. The locking mechanismcan utilize at least one tab and corresponding aperture for mating thedetachable nosecone distal end to the nosecone proximal end. The lockingmechanism may not interfere with cutter's ability to extend past thelocking mechanism. The nosecone can be rigid. The nosecone can beflexible. The nosecone can include both flexible and rigid regions. Theatherectomy catheter can further include a guidewire channel disposed onthe nosecone and the catheter body.

In general, an atherectomy catheter includes a catheter body having acatheter body proximal end, a catheter body distal end, a cuttingwindow, a cutter exposable through the cutting window, a nosecone, acollar, and a locking mechanism for maintaining connection between theproximal and distal ends of the nosecone. A nosecone has a noseconeproximal end and a nosecone distal end. The nosecone proximal end isconfigured to couple and decouple from the nosecone distal end. Thecollar is configured to maintain connection between the noseconeproximal end with the nosecone distal end. The locking mechanismcomponents are disposed on the nosecone proximal end, the collar, thenosecone distal end, or a combination thereof.

This and other embodiments can include one or more of the followingfeatures. The nosecone can further include a hollow interior portionconfigured to receive excised tissue. The locking mechanism can utilizecorresponding threads for mating the nosecone proximal end with thenosecone distal end. The locking mechanism can utilize at least one taband corresponding aperture for mating the nosecone proximal end with thedetachable nosecone distal end. The locking mechanism cannot interferewith the cutter's ability to extend past the locking mechanism. Thenosecone can be rigid. The nosecone can be flexible. The nosecone caninclude both flexible and rigid regions.

In general, an atherectomy catheter includes a catheter body having acatheter body proximal end, a catheter body distal end, a cuttingwindow, a cutter exposable through the cutting window, a nosecone, acollar, and a locking mechanism for maintaining connection between thedetachable nosecone and the catheter body. A nosecone has a noseconeproximal end and a nosecone distal end. The nosecone proximal end isconfigured to couple and decouple from the nosecone distal end. Thecollar is configured to maintain connection between the detachablenosecone and the catheter body. The locking mechanism includescorresponding threads on the collar, nosecone proximal end, or noseconedistal end adapted to couple the proximal and distal ends of thenosecone.

In general, in one embodiment, an atherectomy catheter includes acatheter body having a catheter body proximal end, a catheter bodydistal end, a cutting window, a cutter exposable through the cuttingwindow, a nosecone, a collar, and a locking mechanism for maintainingconnection between the proximal and distal ends of the nosecone. Anosecone has a nosecone proximal end and a nosecone distal end. Thenosecone proximal end is configured to couple and decouple from thenosecone distal end. The collar is configured to maintain connectionbetween the detachable nosecone and the catheter body. The lockingmechanism includes at least one tab disposed on the collar havingcorresponding aperture adapted to mate the proximal and distal ends ofthe nosecone.

This and other embodiments can include one or more of the followingfeatures. The atherectomy catheter can further include a drive systemconfigured to extend and retract the cutter within the nosecone.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1A shows a distal end of an atherectomy catheter having a tissueconnection nosecone with a detachable distal end

FIG. 1B is a perspective view of an exemplary coupling mechanism forcoupling detachable proximal and distal sections of a nosecone. FIG. 1Cshows a cross-section of the coupling mechanism of FIG. 1B. FIG. 1D is aperspective views of a first coupling element of the coupling mechanismof FIG. 1B. FIGS. 1E and 1F shows a perspective view of a secondcoupling element of the coupling mechanism of FIG. 1B.

FIGS. 2A and 2B show an alternative exemplary coupling mechanism for anosecone. FIG. 2A shows a coupling element including two tabs. FIG. 2Bshows a coupling element including to corresponding apertures andconfigured to lock with the coupling element of FIG. 2A.

FIG. 3A shows a top perspective view of a portion of an atherectomycatheter having a nosecone with a detachable distal end that isconnected through a single tab coupling mechanism.

FIG. 3B shows a bottom perspective view of the portion of theatherectomy catheter of FIG. 3A.

FIG. 4A shows a side perspective view of a portion of a nosecone with adetachable distal end that is connected through a twist mechanism.

FIG. 4B shows a bottom view of the portion of the nosecone of FIG. 4A.

FIG. 4C-4E show the nosecone of FIG. 4A with the collar removed so as tomake the twist/aligning features between the proximal and distal endsvisible.

FIG. 5A shows an exemplary nosecone having a detachable distal endactivated by a cam and ball mechanism.

FIG. 5B shows a the cam and ball mechanism.

FIG. 5C shows a close-up of the nosecone of FIG. 5A in the lockedposition with the distal portion of the nosecone removed for clarity.

FIG. 5D shows a cross-section through the locked nosecone shown in FIG.5C.

FIG. 5E shows a close-up of the nosecone of FIG. 5A in the unlockedposition with the distal portion of the nosecone removed for clarity.

FIG. 5F shows a cross-section through the unlocked nosecone shown inFIG. 5E.

FIG. 5G shows the nosecone of FIG. 5A with the distal end detached fromthe proximal end.

FIG. 5H shows a cross-section through FIG. 5B to more clearly show thecam path.

FIG. 6A shows an exemplary nosecone having a detachable distal endactivated by a snap mechanism.

FIG. 6B shows the proximal and distal ends disconnected.

FIG. 6C is a cross-section showing the proximal and distal endsconnected.

FIG. 7 shows a separable nosecone with monorail guidewire lumen.

DETAILED DESCRIPTION

Described herein are atherectomy catheters including an elongate body, acutter, and a nosecone configured to collect debulked tissue. Thenosecone includes an atraumatic distal end, a proximal end that couplesto the remainder of the catheter body, and an interior region forcollecting excised tissue. The proximal portion of the nosecone isdetachable from the distal portion for ease of for ease of cleaningand/or for quick replacement of the distal portion of the noseconeduring an atherectomy procedure.

The nosecones described herein include features that both allow easycoupling of the proximal and distal ends of the nosecone and preventunwanted decoupling during use. Moreover, the interior surface of thenosecone with detachable distal/proximal portions can be substantiallysmooth, allowing a cutter to extend therein (e.g., to pack tissue)without hindrance.

The distal end of an exemplary atherectomy catheter 1200 is shown inFIG. 1A, The atherectomy catheter includes a catheter body 1201, ahollow nosecone 1204, an annular rotatable cutter 1210, and a cutterwindow 1207 through which the cutter can debulk tissue. The hollownosecone 1204 can be configured to collect tissue as it is removed inthe body. Further, in some embodiments, the cutter 1210 can be movedaxially into the nosecone 1204 to pack tissue therein. Moreover, in someembodiments, the nosecone 1204 can hinge relative to the catheter body1201, such as at a pivot point. As shown in FIG. 1A, in someembodiments, the nosecone can include holes 1244 therein for venting. Adistal section or end 1205 of the nosecone 1204 can be configured todetach from the proximal portion 1206 of the nosecone 1200 atattachment/detachment point 1226 to allow for ease of removing collectedor packed tissue. The attachment/detachment point 1226 can include, forexample, one or more coupling elements. Various embodiments of couplingelements are described herein.

FIGS. 1B-1F show an exemplary coupling mechanism 111 that includes afirst coupling element 925 configured to interface with a correspondingcoupling element 1024 for locking and unlocking of the proximal anddistal portions of a nosecone (such as nosecone 1204).

FIG. 1D shows the coupling element 925, which includes a proximal end930 and a distal end 928. The coupling element 925 includes a generallycylindrical main body with a lumen between the proximal and distal ends.The slots or cutouts 932 a-b are formed through the wall of the mainbody. Although shown with two slots having a generally rectangularshape, the coupling element 925 can have any number of slots with anyshape. The shape of the main body is designed to be inserted into thecorresponding coupling element 1024 for attachment.

FIGS. 1E and 1F illustrate the corresponding coupling element 1024 thatis configured to releasably attach to the coupling element 925. Thecorresponding coupling element 1024 is shape set to the coupling element924 such that coupling element 925 can be inserted into thecorresponding coupling element 1024 to form a snug fit (as shown inFIGS. 1B-1C). The corresponding coupling element 1024 has an inner wall1038 that contacts the outer wall 934 of the coupling element 925 whenfitted. Further, the corresponding coupling element 1024 includesprotrusions shown as tabs 1036 a-b that project from its main bodytowards the center. In some embodiments, the tabs 1036 a-b protrude atan angle towards the center of the main body and are configured toextend into the receiving slots 932 a-b.

Thus, in operation, the corresponding coupling element 1024 is placedover the outer wall 924 of the coupling element 925. The proximal end1032 of the corresponding coupling element 1024 is advanced over thedistal end 928 of the coupling element 925. Then the correspondingcoupling element 1024 (or the coupling element 925) is rotated relativeto the other element to align the tabs 1036 a-b with the slots 932 a-b.To lock the coupling elements, an edge of the slots 932 a-b is slid intothe recess 1031 a-b until a portion of the main body of the couplingelement 925 is held between a tab surface and the inner wall of thecorresponding coupling element 1024. FIGS. 1B-1C shows the correspondingcoupling element 1024 surrounding the coupling element 925 with tabs1036 a-b engaged with slots 932 a-b. The tabs 1036 a-b are receivedthrough the slots 932 a-b into an interior of the coupling element 925.The edge of the slots 932 a-b are slid into the recesses 1031 a-b tohold and lock the lateral orientation of the coupling element 925 withinthe corresponding coupling element 1024. As shown, rotating thecorresponding coupling element counter-clockwise disengages the couplingelements and releases the coupling elements from one another.

FIGS. 2A and 2B show variations of the coupling elements shown in FIGS.1B-1F. For example, FIG. 2A shows a corresponding coupling element 1124with two tabs 1136 a-b and a plurality of apertures 1105. In someembodiments, the apertures provide for fluid pressure release. FIG. 2Bshows a coupling element 1125 having slots 1132 a-c, e.g., configured tointeract with tabs 1136 a-b of FIG. 2A. Although the coupling elementsof FIGS. 1B-I F and 2A-2B are shown with two or three tabs/slots, it isto be understood that any number of mating structures can be used toform the detachable tissue collection devices.

FIG. 3A shows another embodiment of a nosecone 204 that can be used withan atherectomy catheter. The nosecone 204 includes a distal end 205 thatis detachable from a proximal end 206 at coupling mechanism 211. Thenosecone distal end 205 is atraumatic.

The nosecone 204 further includes a cutting aperture 207 that allowscutter (e.g., an annular cutter) of the device to be exposedtherethrough for cutting and removing tissue. The nosecone proximal end206 is configured to couple with the remainder of the catheter body,such as at a connection point 202. For example, the catheter body 201can be coupled with the nosecone 204 proximal to the cutting aperture207. In some embodiments, the nosecone 204 can be connected at a hingepoint so as to hinge away from the catheter body.

Referring to FIGS. 3A and 3B, the coupling between the nosecone 204distal end 205 and proximal end 206 may include a collar 211. The collar211, in turn, may be attached permanently to the nosecone proximal end106 as shown. The collar 211 can include a collar aperture 212 that isable to couple to a corresponding feature (e.g. a tab 119 or otherprotrusion) on the proximal end 105 of the nosecone 204. The tab 219 canbe configured to include an amount of flexibility such that a user isable to push the end of the collar 211 past the tab 219 to align the tab219 and the collar aperture 212. The insertion of the distal end 205into the collar 211 can be aided by the angled or beveled distal edge ofthe collar 211.

Once aligned with the collar aperture 212, the tab 219 can be engaged orlocked within the aperture 212 by an extension 221 on the collar 211.The extension 221 is configured to contact the tab 219, causing the tab219 to pivot (e.g., at a flexion point) with the proximal end of the tab219 moving radially towards the central axis of the collar 211 and thedistal end of the tab 219 moving radially away from the central axis ofthe collar 211 to engage/attach within the collar aperture 212 and lockthe tab 219 in place. Once the tab 219 is locked in place, the proximaland distal ends 206, 205 of the nosecone will then be connected and/orlocked together. To disengage the collar 211 from the distal end 205 ofthe nosecone 204, the user can push on the tab to free the tab from thecollar aperture 212 and slide the collar 211 axially away from thedistal end 205 of the nosecone 204.

In an alternative embodiment, the collar 211 may be permanently attachedto the distal end 205 of the nosecone 204 rather than the proximal end206. Here, the proximal end 206 of the nosecone 204 may includecorresponding features with the collar 211 including tabs withcorresponding apertures that are able to mate, corresponding threadsthat screw together, etc.

In some other variations, the collar 211 may be completely detachablefrom both the nosecone proximal end 206 and the nosecone distal end 205.In this design, the collar 211 may have two or more coupling featuresfor mating the nosecone proximal end 206 to the nosecone distal end 205.The coupling features on the collar 211 in this example may also be usedto properly align the nosecone proximal end 206 with the nosecone distalend 205. For example, the collar may have tabs that mate withcorresponding tab acceptors on both the nosecone distal end 205 and thenosecone proximal end 206 for holding the two components together, butin addition, the collar 211 may also have additions features that aidwith ensuring that the nosecone distal end 205 is properly aligned withthe nosecone proximal end 206. These additional features may include,but are not limited to, protrusions and corresponding apertures orslots.

Turning to FIGS. 4A-4E, another coupling mechanism 310 between thedistal end 305 and proximal end 306 of a nosecone 304 is shown. Thecoupling mechanism 310 for the nosecone 304 employs a twist type motionto engage and disengage the nosecone distal end 305 with the noseconeproximal end 306. The twist coupling mechanism 310 is best shown inFIGS. 4C-4E (the collar 311 has been removed in these figures forclarity). The twist coupling mechanism 310 includes a hooked, curved, orc-shaped extension 315 on the distal end 305 that interlock or mateswith a corresponding hooked, curved, or c-shaped extension 316 on theproximal end 306 when the proximal and distal ends 306, 305 are rotatedrelative to one another. Each extension 315, 316 includes a wave-likecurve or bump 326, 325 that fits with the corresponding bump 326, 325 onthe opposite side. To connect the proximal and distal portions 306, 305,the two portions can be rotated relative to one another. To release,they can be rotated in the opposite direction.

Referring back to FIGS. 4A-4B, the collar 311 can be clamped over thetwist mechanism 310 to keep the extensions 315, 316 from rotating apartduring use. The collar 311 can be permanently attached to either theproximal end (as shown in FIGS. 3A-3B) or the distal end. When attachedto the proximal end, the collar 311 can have a beveled or angled distaledge to aid in insertion of the distal end 305 therein.

Another exemplary embodiment of a nosecone 504 is shown in FIGS. 5A-5H.As shown in FIG. 5A, the nosecone 504 includes a proximal end 506 and adetachable distal end 505. The nosecone 504 further includes a couplingmechanism 515 configured to allow for attachment and detachment of thedistal end 505 of the nosecone 504. Referring to FIGS. 5B and 5G, thecoupling mechanism 515 includes a solid plug 571 that fits within, andseals to, the inner diameter of the proximal end 506 of the nosecone504. The coupling mechanism 515 further includes an annular collar 573configured to permanently attach to the proximal end 505 of thenosecone. The coupling mechanism 515 connects together by twisting arotatable tab 525 (which is fixed to the collar 573) to activate a cam577. When the distal end 505 is locked to the proximal end 506 (as shownin FIGS. 5C and 5D), a ball bearing 527 sits within an outer window 533.When unlocked, however, the ball bearing 525 is pulled back inside thewindow 533 into the inner slot 531 (as shown in FIGS. 5E-5F).

In use, the user can grab the tab 525 (e.g., through a flexible portionof the distal end 505), insert the plug 571 into the distal end 505, androtate the tab 525. As shown in FIG. 5G, doing so will cause the peak inthe cam 577 to push the ball 527 from the window 531 towards the window533. Once engaged in the window 533, the ball 527 will prevent futuremovement of the proximal and distal ends 506, 507 relative to oneanother. To unlock, the user can rotate the tab 525 in the oppositedirection. This will cause the ball 527 to move all the way back intothe inner window 531, allowing the distal end 505 to be pulled distallyaway from the proximal end 506.

The coupling mechanisms 515 is positioned close to the distal tip of thenosecone 504 (e.g., 1-2 inches, such as approximately 1.5 inches awayfrom the distal edge of the cutting window 507). This can advantageouslyprovide for ample room for tissue packing inside the proximal portion506 and prevent interference of the coupling mechanism 515 with thecutter as it packs tissue.

Another exemplary embodiment of a nosecone 604 is shown in FIGS. 6A-6C.The nosecone 604 includes a proximal end 606 and a detachable distal end605. The nosecone 604 further includes a coupling mechanism 622configured to allow for attachment and detachment of the distal end 605from the proximal end 606. The coupling mechanism 622 includes a solidplug 671 that fits within, and seals to, the inner diameter of theproximal end 606 of the nosecone. The coupling mechanism 622 furtherincludes two snap arms 623 a,b that extend proximally away from the plug671. The snap arms 623 a,b can further include radially extending tabs625 a,b that are configured to snap into corresponding snap window 624a,b on the proximal end 606. In some embodiments, the user can releasethe distal end 605 by pushing on the tabs 625 a,b. Further, in someembodiments, the tabs 625 a,b can be chamfered at one edge such thateither clockwise or counterclockwise rotation can automatically push thetabs 625 a,b to release the coupling mechanism 622.

Again, the coupling mechanism 622 is positioned close to the distal tipof the nosecone 604 (e.g., there can be about 1-2 inches, such as 1.5inches, from a distal edge of the cutter window 607 to a proximal end ofthe snap arms). This can advantageously provide for ample room fortissue packing inside the proximal portion 606 and prevent interferenceof the coupling mechanism 622 with the cutter as it packs tissue.

Referring to FIG. 7, in any of the embodiments described herein, aguidewire lumen 755 can extend down the side of the nosecone. Theguidewire lumen 755 can include two interconnectable sections (onesection attached to the proximal end 706 and another section attached tothe distal end 705). Insertion of the guidewire through the lumen 755can help keep the proximal and distal ends 706, 705 of the noseconetogether. That is, the insertion of the guidewire through the lumen 755can help prevent rotation of the proximal and distal ends 706, 705relative to one another when a rotatable or twisting locking mechanism710 is used to unlock (e.g., any of the embodiments described hereinthat include twisting or rotation to unlock).

In some embodiments, features on both the nosecone distal end and thenosecone proximal end may aid a user in properly aligning the noseconeproximal end with the nosecone distal end. For example, in someinstances, the nosecone proximal end and the nosecone distal end may beangled or biased such that they fit together. To further ensure properalignment or attachment of these two components, the nosecone proximalend and the catheter distal end may further include features on theangled or biased end surfaces that are configured to mate. In otherexamples, there may be visual indicators on the nosecone proximal endand the catheter body distal end that aid a user in aligning the twoportions.

In some embodiments, the attachment features can include an auditory orphysical signal that indicates that the proximal and distal ends of thenosecone are connected (e.g., the detent feature can make a clickingnoise to signal locking).

In some embodiments, the attachment mechanisms and distal ends of thenosecones described herein can be reusable. In other embodiments, thedistal end of the nosecone is meant as a single use, and the attachmentmechanisms cannot be detached and then reattached. For example, the tabfeatures can be configured to break or become unusable after disengaged.

The attachment mechanisms shown with respect to FIGS. 3A-6C have asubstantially smooth inner circumference (i.e., on the inside of thenosecone) and are free of tabs or mechanisms that extend radiallyinwards into the nosecone. This can advantageously prevent theattachment mechanisms from interfering with the movement of the cutteras it is moved into the nosecone (i.e., for packing) and/or preventpieces of excised plaque or tissue from becoming entangled on radiallyinwardly protruding extensions of the attachment mechanisms.

In some embodiments, the nosecone attachment mechanisms described hereinare a set distance from the cutting window to further eliminateinterference with the cutter. Thus, the distance between the attachmentmechanism and the cutting window can be, for example, 0.5″-1.0″, such as0.6″-0.8″, such as approximately 0.68″ or 0.70″. In some embodiments,the distal edge of the cutter, when fully extended, can be positionedjust proximal of the attachment mechanisms.

It should be understood that any suitable mechanism or means (e.g.friction fit, mated fit, threaded fit, hooks, securing members, etc.)may be used in addition to, or in place of, the attachment mechanismsdescribed herein to detach a portion or the entirety of a tissuecollection device to another device.

Additionally, any suitable materials such as nitinol, stainless steel(e.g. grade 304), or titanium or alloys may be used to form theattachment mechanisms. Coatings including gold or platinum may be usedto promote radiopacity.

Any of the features of the described tissue collection devices can beused in combination without departing from the disclosure.

Having a nosecone with detachable sections therein can advantageously beused for flushing or otherwise clearing excised tissue out of thenosecone. That is, after tissue has been excised and collected in thenosecone (such as by packing it into the nosecone through axial movementof the cutter), the distal end or section of the nosecone can beremoved, thereby permitting the proximal end to be flushed (e.g., fromthe cutting window through the open distal end) and/or allowing eitherthe proximal or the distal end to be easily cleared with a tissueremoval tool.

Although the above coupling mechanisms have been described as being usedto attach and detach to portions of a nosecone, they can also be used tocouple other portions of a catheter. For example, in some embodiments,the entire tissue-collection portion of the nosecone can be removablefrom the rest of the catheter using one of the coupling mechanismsdescribed herein.

Any of the described tissue collection devices can be used withatherectomy or other occlusion crossing devices. In such cases, theatherectomy devices typically include an elongate body and a rotatabletip (with a cutter) at the first distal end of the elongate body andconfigured to rotate relative to the elongate body. Such devices aredescribed in U.S. Patent Application No. 61/646,843, titled “ATHERECTOMYCATHETERS WITH IMAGING,” filed on May 14, 2012, U.S. patent applicationSer. No. 13/433,049, titled “OCCLUSION-CROSSING DEVICES, IMAGING, ANDATHERECTOMY DEVICES,” filed Mar. 28, 2012, U.S. patent application Ser.No. 13/175,232, titled “ATHERECTOMY CATHETERS WITH LONGITUDINALLYDISPLACEABLE DRIVE SHAFTS,” filed on Jul. 1, 2011, U.S. patentapplication Ser. No. 12/829,277, titled “ATHERECTOMY CATHETER WITHLATERALLY-DISPLACEABLE TIP,” filed on Jul. 1, 2010, and U.S. patentapplication Ser. No. 12/829,267, titled “CATHETER-BASED OFF-AXIS OPTICALCOHERENCE TOMOGRAPHY IMAGING SYSTEM,” filed on Jul. 1, 2010,International Patent Application No. PCT/US2015/014613, titled“ATHERECTOMY CATHETERS AND OCCLUSION CROSSING DEVICES,” filed on Feb. 5,2015, U.S. patent application Ser. No. 15/072,272, titled “ATHERECTOMYCATHETERS DEVICES HAVING MULTI-CHANNEL BUSHINGS,” filed on Mar. 16,2016, and U.S. patent application Ser. No. 15/076,568, titled“ATHERECTOMY CATHETERS AND OCCLUSION CROSSING DEVICES,” filed on Mar.21, 2016, all of which are herein incorporated by reference in theirentirety.

When a feature or element is herein referred to as being “on” anotherfeature or element, it can be directly on the other feature or elementor intervening features and/or elements may also be present. Incontrast, when a feature or element is referred to as being “directlyon” another feature or element, there are no intervening features orelements present. It will also be understood that, when a feature orelement is referred to as being “connected”, “attached” or “coupled” toanother feature or element, it can be directly connected, attached orcoupled to the other feature or element or intervening features orelements may be present. In contrast, when a feature or element isreferred to as being “directly connected”, “directly attached” or“directly coupled” to another feature or element, there are nointervening features or elements present. Although described or shownwith respect to one embodiment, the features and elements so describedor shown can apply to other embodiments. It will also be appreciated bythose of skill in the art that references to a structure or feature thatis disposed “adjacent” another feature may have portions that overlap orunderlie the adjacent feature.

Terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention.For example, as used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, steps, operations, elements, components, and/orgroups thereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items and may beabbreviated as “/”.

Spatially relative terms, such as “under”, “below”, “lower”, “over”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if a device in thefigures is inverted, elements described as “under” or “beneath” otherelements or features would then be oriented “over” the other elements orfeatures. Thus, the exemplary term “under” can encompass both anorientation of over and under. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly. Similarly, the terms“upwardly”, “downwardly”, “vertical”, “horizontal” and the like are usedherein for the purpose of explanation only unless specifically indicatedotherwise.

Although the terms “first” and “second” may be used herein to describevarious features/elements (including steps), these features/elementsshould not be limited by these terms, unless the context indicatesotherwise. These terms may be used to distinguish one feature/elementfrom another feature/element. Thus, a first feature/element discussedbelow could be termed a second feature/element, and similarly, a secondfeature/element discussed below could be termed a first feature/elementwithout departing from the teachings of the present invention.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” and “comprising” means various components can be co-jointlyemployed in the methods and articles (e.g., compositions and apparatusesincluding device and methods). For example, the term “comprising” willbe understood to imply the inclusion of any stated elements or steps butnot the exclusion of any other elements or steps.

As used herein in the specification and claims, including as used in theexamples and unless otherwise expressly specified, all numbers may beread as if prefaced by the word “about” or “approximately,” even if theterm does not expressly appear. The phrase “about” or “approximately”may be used when describing magnitude and/or position to indicate thatthe value and/or position described is within a reasonable expectedrange of values and/or positions. For example, a numeric value may havea value that is +/−0.1% of the stated value (or range of values), +/−1%of the stated value (or range of values), +/−2% of the stated value (orrange of values), +/−5% of the stated value (or range of values), +/−10%of the stated value (or range of values), etc. Any numerical rangerecited herein is intended to include all sub-ranges subsumed therein.

Although various illustrative embodiments are described above, any of anumber of changes may be made to various embodiments without departingfrom the scope of the invention as described by the claims. For example,the order in which various described method steps are performed mayoften be changed in alternative embodiments, and in other alternativeembodiments one or more method steps may be skipped altogether. Optionalfeatures of various device and system embodiments may be included insome embodiments and not in others. Therefore, the foregoing descriptionis provided primarily for exemplary purposes and should not beinterpreted to limit the scope of the invention as it is set forth inthe claims.

The examples and illustrations included herein show, by way ofillustration and not of limitation, specific embodiments in which thesubject matter may be practiced. As mentioned, other embodiments may beutilized and derived there from, such that structural and logicalsubstitutions and changes may be made without departing from the scopeof this disclosure. Such embodiments of the inventive subject matter maybe referred to herein individually or collectively by the term“invention” merely for convenience and without intending to voluntarilylimit the scope of this application to any single invention or inventiveconcept, if more than one is, in fact, disclosed. Thus, althoughspecific embodiments have been illustrated and described herein, anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

What is claimed is:
 1. An atherectomy catheter comprising: an elongatecatheter body; a cutter at a distal end of the catheter body configuredto excise tissue from the body; and a nosecone attached to a distal endof the catheter body and configured to hold tissue excised from thecutter, wherein the nosecone includes a distal section, a proximalsection, and a connection mechanism therebetween that is configured toallow the distal section to attach and detach from the proximal sectionduring use, further wherein the distal section includes a plugconfigured to sit within an inner diameter of the proximal section whenthe proximal section is connected to the distal section.
 2. Theatherectomy catheter of claim 1, wherein the nosecone further comprisesa hollow interior portion configured to receive excised tissue.
 3. Theatherectomy catheter of claim 1, wherein the nosecone is flexible. 4.The atherectomy catheter of claim 1, further comprising a guidewirechannel disposed along an exterior of the nosecone.
 5. The atherectomycatheter of claim 4, wherein the guidewire channel comprises a distalportion extending along the distal section of the nosecone and aproximal portion extending along the proximal section of the nosecone,the distal portion and proximal portion configured to align when theproximal section and the distal section are connected together.
 6. Theatherectomy catheter of claim 5, further wherein the distal portion andproximal portions are configured to prevent the proximal section anddistal sections from rotating relative to one another when a guidewireis placed therethrough.
 7. The atherectomy catheter of claim 1, whereinthe connection mechanism further includes a tab configured to be grippedthrough the distal section of the nosecone to rotate the distal sectionrelative to the proximal section to activate or deactivate theconnection mechanism.
 8. The atherectomy catheter of claim 1, whereinthe connection mechanism further include a cam and ball bearingconfigured to lock and unlock the proximal section relative to thedistal section.
 9. The atherectomy device of claim 1, wherein theconnection mechanism includes a plurality of snap arms configured toextend into the proximal section and to interlock with apertures on theproximal section.
 10. The atherectomy device of claim 9, wherein thesnap arms each include a tab configured to fit within the apertures. 11.The atherectomy device of claim 10, wherein the tabs are chamfered alonga side edge such that rotation of the distal section towards thechamfered edges causes the distal section to automatically unlock fromthe proximal section.
 12. The atherectomy device of claim 1, wherein thenosecone is configured to pivot away from the elongate catheter body tofurther expose the cutter.
 13. The atherectomy device of claim 1,wherein the cutter is configured to move axially into the nosecone topack tissue.
 14. An atherectomy catheter comprising: a catheter bodyhaving a catheter body proximal end, a catheter body distal end, acutting window, and a cutter exposable through the cutting window; anosecone having a nosecone proximal end and a nosecone distal end,wherein the nosecone proximal end is configured to couple and decouplefrom the nosecone distal end; and a collar having a collar inner surfaceconfigured to maintain a detachable connection between the noseconeproximal end with the nosecone distal end.
 15. The atherectomy catheterof claim 14, wherein the nosecone further comprises a hollow interiorportion configured to receive excised tissue.
 16. The atherectomycatheter of claim 14, further comprising a locking mechanism formaintaining connection between the nosecone proximal end with thenosecone distal end. wherein the locking mechanism components aredisposed on the nosecone proximal end, the collar, the nosecone distalend, or a combination thereof.
 17. The atherectomy catheter of claim 16,wherein the locking mechanism utilizes corresponding threads for matingthe detachable nosecone proximal end to the nosecone distal end.
 18. Theatherectomy catheter of claim 16, wherein the locking mechanism utilizesat least one tab and corresponding aperture for mating the detachablenosecone distal end to the nosecone proximal end.
 19. The atherectomycatheter of claim 17 or 18, wherein the locking mechanism does notinterfere with cutter's ability to extend past the locking mechanism.20. The atherectomy catheter of claim 14, wherein the nosecone is rigid.21. The atherectomy catheter of claim 14, wherein the nosecone isflexible.
 22. The atherectomy catheter of claim 14, wherein the noseconecomprises both flexible and rigid regions.
 23. The atherectomy catheterof claim 14, further comprising a guidewire channel disposed on thenosecone and the catheter body.
 24. An atherectomy catheter comprising:a catheter body having a catheter body proximal end, a catheter bodydistal end, a cutting window, and a cutter exposable through the cuttingwindow; a nosecone having a nosecone proximal end and a nosecone distalend, wherein the nosecone proximal end is configured to couple anddecouple from the nosecone distal end; and a collar configured tomaintain connection between the nosecone proximal end with the noseconedistal end; and a locking mechanism for maintaining connection betweenthe proximal and distal ends of the nosecone, wherein the lockingmechanism components are disposed on the nosecone proximal end, thecollar, the nosecone distal end, or a combination thereof.
 25. Theatherectomy catheter of claim 24, wherein the nosecone furthercomprising a hollow interior portion configured to receive excisedtissue.
 26. The atherectomy catheter of claim 24, wherein the lockingmechanism utilizes corresponding threads for mating the noseconeproximal end with the nosecone distal end.
 27. The atherectomy catheterof claim 16, wherein the locking mechanism utilizes at least one tab andcorresponding aperture for mating the nosecone proximal end with thedetachable nosecone distal end.
 28. The atherectomy catheter of claim 26or 27, wherein the locking mechanism does not interfere with cutter'sability to extend past the locking mechanism.
 29. The atherectomycatheter of claim 24, wherein the nosecone is rigid.
 30. The atherectomycatheter of claim 24, wherein the nosecone is flexible.
 31. Theatherectomy catheter of claim 24, wherein the nosecone comprises bothflexible and rigid regions.
 32. An atherectomy catheter, the devicecomprising: a catheter body having a catheter body proximal end, acatheter body distal end, a cutting window, and a cutter exposablethrough the cutting window; a nosecone having a nosecone proximal endand a nosecone distal end, wherein the nosecone proximal end isconfigured to couple and decouple from the nosecone distal end; and acollar configured to maintain connection between the detachable noseconeand the catheter body; and a locking mechanism for maintainingconnection between the detachable nosecone and the catheter body whereinthe locking mechanism comprises corresponding threads on the collar,nosecone proximal end, or nosecone distal end adapted to couple theproximal and distal ends of the nosecone.
 33. An atherectomy cathetercomprising: a catheter body having a catheter body proximal end, acatheter body distal end, a cutting window, and a cutter exposablethrough the cutting window; a nosecone having a nosecone proximal endand a nosecone distal end, wherein the nosecone proximal end isconfigured to couple and decouple from the nosecone distal end; a collarconfigured to maintain connection between the detachable nosecone andthe catheter body; and a locking mechanism for maintaining connectionbetween the proximal and distal ends of the nosecone, wherein thelocking mechanism comprises at least one tab disposed on the collarhaving corresponding aperture adapted to mate the proximal and distalends of the nosecone.
 34. The atherectomy catheter of any claim above,further comprising a drive system configured to extend and retract thecutter within the nosecone.